Nodes and methods for enhancing positioning

ABSTRACT

The disclosure relates to a positioning node  54 , a CN node  53 , a RN node  52 , and a UE  51  of a wireless network, and to a related method of supporting UE positioning. The method comprises transmitting UE radio access capability information (S 30 ) and/or radio network node capability information (S 10 ) to the positioning node  54 . The transmission of UE radio access capability information is either unsolicited or triggered by a request (S 20 ). The UE radio access capability information may be transmitted from the CN node (S 31 ), from the RN node (S 32 ) or from the UE (S 33 ), and the RN node capability information is received from the RN node itself (S 10 ). The positioning node  54  supports positioning of the UE  51  based on the received UE radio access capability information and/or the radio network node capability information.

TECHNICAL FIELD

The present invention relates to a method of supporting positioning of awireless device in a positioning node, in a wireless device, in a radionetwork node, and in a core network node of a wireless communicationsystem. The invention also relates to a positioning node, a wirelessdevice, a radio network node, and a core network node of a wirelesscommunication system.

BACKGROUND

The Universal Mobile Telecommunication System (UMTS) is one of the thirdgeneration mobile communication technologies designed to succeed GSM.3GPP Long Term Evolution (LTE) is a project within the 3^(rd) GenerationPartnership Project (3GPP) to improve the UMTS standard to cope withfuture requirements in terms of improved services such as higher datarates, improved efficiency, and lowered costs. The Universal TerrestrialRadio Access Network (UTRAN) is the radio access network of a UMTS andEvolved UTRAN (E-UTRAN) is the radio access network of an LTE system. Inan E-UTRAN, a wireless device such as a user equipment (UE) 150 iswirelessly connected to a radio base station (RBS) 110 a commonlyreferred to as an evolved NodeB (eNodeB), as illustrated in FIG. 1 a.Each eNodeB 110 a-c serves one or more areas each referred to as cells120 a-c, and are connected to the core network. In LTE, the eNodeBs 110a-c are connected to a Mobility Management Entity (MME) 130 in the corenetwork. A positioning node, also called a location server, in thecontrol plane architecture in FIG. 1 a is connected to the MME 130. Thepositioning node is a physical or logical entity that managespositioning for a so called target device, i.e. a wireless device thatis being positioned, and is in the control plane architecture referredto as an Evolved Serving Mobile Location Center (E-SMLC) 140. Asillustrated in FIG. 1 a, the E-SMLC 140 may be a separate network node,but it may also be a functionality integrated in some other networknode. In a user plane architecture, the positioning is a part of aSecure User Plane Location (SUPL) Location Platform (SLP). Hereinafter,the general term wireless device may be a UE, a laptop, a small radionode or base station, a relay, or a sensor. The UE may be a mobiletelephone, a pager, a headset, a laptop computer and other mobileterminals. The wireless device may also refer to a device or node beingpositioned in general, often referred to as a Location Service (LCS)target. LTE Positioning Protocol (LPP) and LTE Positioning Protocolannex (LPPa) are protocols used for carrying out positioning in thecontrol plane architecture in LTE. LPP is also used in the user planearchitecture, whilst LPPa may be used to support user plane positioning.There may also be LPP extensions, e.g. LPPe, which may be included inLPP messages. When receiving a positioning request, the E-SMLC mayrequest positioning related parameters from eNodeB via LPPa. The E-SMLCthen assembles and sends assistance data and the request for thepositioning to the target wireless device, e.g. the UE, via LPP. FIGS. 1b-c illustrate example architectures and protocol solutions of apositioning system in an LTE network. In the control plane solution,illustrated in FIG. 1 b, the UE communicates with the E-SMLCtransparently via the eNodeB and the MME over LPP, and the eNodeBcommunicates with the E-SMLC transparently via the MME over LPPa. Theuser plane solution illustrated in FIG. 1 c does not rely on the LPPaprotocol, although 3GPP allows for the possibility of inter-workingbetween the control and user plane positioning architectures. The SLP isthe positioning node for user-plane positioning, similar to E-SMLC forcontrol plane positioning, and there may or may not be an interfacebetween the two positioning servers.

UE positioning is a process of determining UE coordinates in space. Oncethe coordinates are available, they may be mapped to a certain place orlocation. The mapping function and delivery of the location informationon request are parts of a location service which is required for basicemergency services. Services that further exploit a location knowledgeor that are based on the location knowledge to offer customers someadded value are referred to as location-aware and location-basedservices. The possibility of identifying a wireless device'sgeographical location in the network has enabled a large variety ofcommercial and non-commercial services, e.g., navigation assistance,social networking, location-aware advertising, and emergency calls.Different services may have different positioning accuracy requirementsimposed by an application. Furthermore, requirements on the positioningaccuracy for basic emergency services defined by regulatory bodies existin some countries. An example of such a regulatory body is the FederalCommunications Commission regulating the area of telecommunications inthe United States.

In many environments, a wireless device position can be accuratelyestimated by using positioning methods based on Global PositioningSystem (GPS). Nowadays, networks also often have a possibility to assistwireless devices in order to improve the device receiver sensitivity andGPS start-up performance, as for example in an Assisted-GPS (A-GPS)positioning method. GPS or A-GPS receivers, however, may not necessarilybe available in all wireless devices. Furthermore, GPS is known to oftenfail in indoor environments and urban canyons. A complementaryterrestrial positioning method, called Observed Time Difference ofArrival (OTDOA), has therefore been standardized by 3GPP. In addition toOTDOA, the LTE standard also specifies methods, procedures, andsignaling support for Enhanced Cell ID (E-CID) and Assisted-GlobalNavigation Satellite System (A-GNSS) positioning. In future, Uplink TimeDifference of Arrival (UTDOA) may also be standardized for LTE.

E-CID Positioning

With E-CID, the following sources of position information are involved:the Cell Identification (CID) and the corresponding geographicaldescription of the serving cell, the Timing Advance (TA) of the servingcell, the CIDs and the corresponding signal measurements of the cells(up to 32 cells in LTE, including the serving cell), as well as Angle ofArrival (AoA) measurements. The following UE measurements can beutilized for E-CID in LTE: E-UTRA carrier Received Signal StrengthIndicator (RSSI), Reference Signal Received Power (RSRP), ReferenceSignal Received Quality (RSRQ), and UE receive-transmit (Rx-Tx) timedifference. The E-UTRAN measurements available for E-CID are eNodeBRx-Tx time difference, TA Type 1 corresponding to (eNodeB Rx-Tx timedifference)+(UE Rx-Tx time difference), TA Type 2 corresponding toeNodeB Rx-Tx time difference, and uplink (UL) AoA. UE Rx-Tx measurementsare typically used for the serving cell, and e.g. RSRP and RSRQ as wellas AoA can be utilized for any cell and can also be conducted on afrequency different from that of the serving cell.

UE E-CID measurements are reported by the UE to the positioning serverover the LPP, and the E-UTRAN E-CID measurements are reported by theeNodeB to the positioning node over the LPPa.

OTDOA Positioning

With OTDOA, a wireless device such as a UE measures the timingdifferences for downlink reference signals received from multipledistinct locations. For each measured neighbor cell, the UE measuresReference Signal Time Difference (RSTD) which is the relative timingdifference between a neighbor cell and the reference cell. Asillustrated in FIG. 2, the UE position estimate is then found as theintersection 230 of hyperbolas 240 corresponding to the measured RSTDs.At least three measurements from geographically dispersed RBSs 210 a-cwith a good geometry are needed to solve for two coordinates of the UE.In order to find the position, precise knowledge of transmitterlocations and transmit timing offsets is needed. Position calculationsmay be conducted, for example by a positioning node such as the E-SMLCor the SLP in LTE, or by the UE. The former approach corresponds to theUE-assisted positioning mode, and the latter corresponds to the UE-basedpositioning mode.

In UTRAN Frequency Division Duplex (FDD), an SFN-SFN type 2 measurement(SFN stands for System Frame Number) performed by the UE is used for theOTDOA positioning method. This measurement is the relative timingdifference between cell j and cell i based on the primary Common PilotChannel (CPICH) from cell j and cell i. The UE reported SFN-SFN type 2is used by the network to estimate the UE position. The OTDOA and otherpositioning methods such as E-CID are to be used also for emergencycalls. Hence the response time of these measurements should be as low aspossible to meet the emergency call requirements.

Positioning Reference Signals

To enable positioning in LTE and facilitate positioning measurements ofa proper quality and for a sufficient number of distinct locations, newphysical signals dedicated for positioning, such as positioningreference signals, (PRS) have been introduced, and low-interferencepositioning subframes have been specified in 3GPP. PRS are transmittedfrom one antenna port according to a pre-defined pattern, as describedin more detail below.

A frequency shift, which is a function of a Physical Cell Identity(PCI), can be applied to the specified PRS patterns to generateorthogonal patterns and model the effective frequency reuse of six (R6),which makes it possible to significantly reduce neighbor cellinterference on the measured PRS and thus improve positioningmeasurements. Even though PRS have been specifically designed forpositioning measurements and in general are characterized by bettersignal quality than other reference signals, the standard does notmandate using PRS. Other reference signals, e.g., cell-specificreference signals (CRS) may also be used for positioning measurements.

PRS are transmitted in pre-defined positioning subframes grouped by anumber N_prs of consecutive subframes, i.e. one positioning occasion, asillustrated in FIG. 3. Positioning occasions occur periodically with acertain periodicity of N subframes, corresponding to a time intervalT_prs between two positioning occasions. The standardized time intervalsT_prs are 160, 320, 640, and 1280 ms, and the number of consecutivesubframes N_prs are 1, 2, 4, and 6.

General UE Radio Access Capability

The UE radio access capability parameters that are currently specifiedin the 3GPP technical specification TS 36.306 comprise:

-   -   ue-Category, which indicates e.g. the maximum number of        supported layers for spatial multiplexing in downlink;    -   Radio Frequency (RF) parameters, such as supportedBandListEUTRA        which defines what E-UTRA RF bands that are supported by the UE.        For each band, support for either only half duplex operation, or        full duplex operation is indicated. For Time Division Duplex        (TDD), the half duplex indication is not applicable;    -   Measurement parameters, such as interFreqNeedForGaps and        interRAT-NeedForGaps. These parameters define for each supported        E-UTRA band whether measurement gaps are required to perform        measurements on other supported E-UTRA radio frequency bands and        on each supported RAT/band combination;    -   Inter-RAT parameters, which are used e.g. for indication of the        supported band lists for UTRA FDD, UTRA TDD, GSM/EDGE Radio        Network (GERAN);    -   General parameters, such as accessStratumRelease which defines        the release of the E-UTRA layer 1, 2, and 3 specifications        supported by the UE e.g. Rel-8 and Rel-9, and deviceType which        defines whether the device does not benefit from NW-based        battery consumption optimisation;    -   Closed Subscriber Group (CSG) Proximity Indication parameters,        such as intraFreqProximitylndication,        interFreqProximitylndication and utran-ProximityIndication which        define whether the UE supports proximity indication in the RAT        (E-UTRAN or UTRAN) cells comprised in the UE's CSG whitelist.        The indication is thus used to inform whether the UE is able to        report that it is entering or leaving the proximity of cell(s)        included in its CSG whitelist, wherein the CSG whitelist may        either be manually entered via a UE interface or autonomously        detected by the UE;    -   Neighbor cell System Information (SI) acquisition parameters,        such as intraFreqSI-AcquisitionForHO,        interFreqSI-AcquisitionForHO, utran-SI-AcquisitionForHO which        define whether the UE supports acquisition of relevant        information from a neighboring intra-frequency cell by reading        the SI of the neighboring cell using autonomous gaps, and        reporting of the acquired information to the network.

The currently defined UE radio access capabilities and the lack ofassociated information available in the network and especially in thepositioning node, have an impact on the positioning measurementrequirements and on positioning performance, and causes unnecessaryoperations and procedures performed by the network.

SUMMARY

An object is therefore to address some of the problems and disadvantagesoutlined above, and to transmit radio access capability associated witha wireless device such as the UE radio access capabilities describedpreviously, and/or radio network node capability information to thepositioning node, allowing the positioning node to use either or bothreceived capability information for supporting positioning.

This object and others are achieved by the methods, wireless device andnodes according to the independent claims, and by the embodimentsaccording to the dependent claims.

In accordance with an embodiment, a method in a positioning node of awireless communication system, of supporting wireless devicepositioning, is provided. The method comprises receiving at least one ofthe following: radio access capability information associated with awireless device; and capability information associated with a radionetwork node from said radio network node. The method also comprisessupporting positioning of the wireless device based on the receivedradio access capability information associated with the wireless deviceand/or the capability information associated with the radio networknode.

In accordance with another embodiment, a method in a wireless device ofa wireless communication system of supporting positioning of thewireless device is provided. The positioning is managed by a positioningnode. The method comprises transmitting radio access capabilityinformation associated with the wireless device to the positioning node.

In accordance with still another embodiment, a method in a radio networknode of a wireless communication system of supporting positioning of awireless device controlled by the radio network node is provided. Thepositioning is managed by a positioning node connected to the radionetwork node. The method comprises transmitting at least one of thefollowing to the positioning node: radio access capability informationassociated with the wireless device, and capability informationassociated with the radio network node.

In accordance with a further embodiment, a method in a core network nodeof a wireless communication system of supporting positioning of awireless device associated with the core network node is provided. Thepositioning is managed by a positioning node connected to the corenetwork node. The method comprises transmitting radio access capabilityinformation associated with the wireless device to the positioning node.

In accordance with another embodiment, a positioning node for a wirelesscommunication system is provided. The positioning node comprises areceiving unit adapted to receive at least one of the following: radioaccess capability information associated with a wireless device; andcapability information associated with a radio network node from saidradio network node. The positioning node also comprises a positioningsupport unit adapted to support positioning of the wireless device basedon the received at least one of the radio access capability informationassociated with the wireless device and the capability informationassociated with the radio network node.

In accordance with still another embodiment, a wireless device for awireless communication system is provided. The wireless device isconfigured to support positioning managed by a positioning node, andcomprises a transmitting unit adapted to transmit radio accesscapability information associated with the wireless device to thepositioning node.

In a further embodiment, a radio network node for a wirelesscommunication system is provided. The radio network node is configuredto support positioning of a wireless device controlled by the radionetwork node. The positioning is managed by a positioning nodeconnectable to the radio network node. The radio network node comprisesa transmitting unit adapted to transmit at least one of the following tothe positioning node: radio access capability information associatedwith the wireless device, and capability information associated with theradio network node.

In another embodiment, a core network node for a wireless communicationsystem is provided. The core network node is configured to supportpositioning of a wireless device associated with the core network node.The positioning is managed by a positioning node connectable to the corenetwork node. The core network node comprises a transmitting unitadapted to transmit radio access capability information associated withthe wireless device to the positioning node.

An advantage of particular embodiments is that the target wirelessdevice positioning accuracy and/or the positioning measurementperformance is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a block diagram schematically illustrating a conventionalwireless communication system.

FIGS. 1 b-1 c are block diagrams schematically illustrating positioningrelated entities and protocols in LTE.

FIG. 2 is a block diagram illustrating the OTDOA principle.

FIG. 3 illustrates the positioning subframe allocation in time for acell.

FIGS. 4 a-c are signaling diagrams illustrating different cases oftransfer of capability information between nodes in the network.

FIGS. 4 d-g illustrate information elements defined in 3GPP.

FIG. 5 is a signaling diagram schematically illustrating the signalingaccording to embodiments of the invention.

FIG. 6 is a flowchart of the method in the positioning node according toembodiments.

FIG. 7 is a flowchart of the method in the wireless device according toembodiments.

FIG. 8 is a flowchart of the method in the radio network node accordingto embodiments.

FIG. 9 is a flowchart of the method in the core network node accordingto embodiments.

FIGS. 10 a-d are block diagrams illustrating the wireless device and thenetwork nodes according to embodiments.

DETAILED DESCRIPTION

In the following, different aspects will be described in more detailwith references to certain embodiments and to accompanying drawings. Forpurposes of explanation and not limitation, specific details are setforth, such as particular scenarios and techniques, in order to providea thorough understanding of the different embodiments. However, otherembodiments that depart from these specific details may also exist.

Moreover, those skilled in the art will appreciate that while theembodiments are primarily described in form of methods and nodes, theymay also be embodied in a computer program product as well as in asystem comprising a computer processor and a memory coupled to theprocessor, wherein the memory is encoded with one or more programs thatmay perform the method steps disclosed herein.

Embodiments are described herein by way of reference to particularexample scenarios. Particular aspects are described in a non-limitinggeneral context in relation to positioning in an LTE system, and to a UEas a positioning target device. It should though be noted that theembodiments may also be applied to other types of radio access networkswith support for positioning, and to other types of positioning targetdevices such as small RBSs or relays.

This disclosure relates to procedures and signaling for increasing theawareness about UE and radio network node capabilities in thepositioning node in order to improve positioning performance in currentand future wireless networks, but also to ensure consistentconfiguration of the positioning measurement session and transmittingthe relevant assistance data in e.g. LTE.

In embodiments the problem of creating the assistance data in the E-SMLCin LTE Release 9 of the 3GPP Technical Specifications without havingknowledge of the UE radio access capabilities or the radio network nodecapabilities is addressed by a solution based on the following parts:

-   1. Signaling of the standardized UE radio access capability    information to the positioning node from various possible sources;-   2. Signaling of UE multi-carrier and carrier-aggregation related    capability information to the positioning node from various possible    sources;-   3. Signaling of radio network node capability information to the    positioning node;-   4. Methods and procedures in the positioning node involving the    signaling above and utilizing the obtained capability information;-   5. Methods and procedures in a radio network node exploiting the UE    radio access capability information to facilitate positioning    measurements;-   6. Methods and procedures enhancing positioning performance in    heterogeneous networks;-   7. Methods and procedures to enhance energy saving in the UE and    radio network nodes by optimizing positioning configuration while    utilizing the capability information signaled as described above;-   8. Apparatus configured to carry out the foregoing signaling,    methods and procedures;

If not explicitly stated, signaling between two nodes implies eithersignaling over direct physical links or signaling over logical links,e.g., involving higher-layer protocols such as LPP or LPPa describedabove.

The UE radio access capability parameters that are currently specifiedin the 3GPP technical specification TS 36.306 and that are listed in thebackground section, are signaled as defined in 3GPP TS 36.331. Thetransfer of the UE radio access capabilities, illustrated in thesignaling diagram in FIG. 4 a is initiated by E-UTRAN 41 for a UE 40 inRRC CONNECTED state when the network needs additional UE radio accesscapability information. The E-UTRAN 41 sends a UECapabilityEnquirymessage in S1 and the UE 40 returns a UECapabilitylnformation in S2. Ifthe UE has changed its E-UTRAN radio access capabilities, the UE shallrequest higher layers to initiate the necessary NAS procedures thatwould result in the update of UE radio access capabilities using a newRadio Resource Control (RRC) connection.

The UE radio access capability is not provided directly from one CoreNetwork (CN) node to another. It will be uploaded to the MME when theE-UTRAN requests the UE radio access capability information from the UE.To avoid transmission of the capability information at each transitionfrom idle state—when there is no NAS signalling connection between UEand network and the UE performs cell selection/reselection and PublicLand Mobile Network (PLMN) selection—to connected state, the MME storesthe UE radio access capability information during idle state.Furthermore, the MME shall, if the information is available, send itsmost up to date UE radio access capability information to the E-UTRAN inthe S1 interface INITIAL CONTEXT SETUP REQUEST message, unless the UE isperforming an Attach procedure or a Tracking Area Update (TAU) procedurefor the first TAU following GERAN/UTRAN attach or for a UE radio accesscapability update. In the latter cases, the MME shall delete or mark asdeleted any UE radio access capability information that it has stored.If the UE is performing a Service Request or other procedure and the MMEdoes not have UE radio access capability information available or doeshave UE radio access capability information marked as deleted, then theMME sends an S1 interface INITIAL CONTEXT SETUP REQUEST message to theE-UTRAN without any UE radio access capability information in it. Thistriggers the E-UTRAN to request the UE radio access capabilityinformation from the UE and to upload it to the MME in the S1 interfaceUE CAPABILITY INFO INDICATION message.

Consequently, the standardized UE radio access capabilities are known toMME and to the eNodeB, but they are not known to the positioning node.The only UE capabilities that are communicated to the positioning nodeaccording to prior art are the UE positioning capabilities, as describedhereinafter.

UE Positioning Capability Transfer From MME to Positioning Node

SLs is the interface between MME and the positioning node E-SMLC. TheSLs interface is used to convey Location Service Application Protocol(LCS-AP) messages between these two nodes. The initiator of the locationservice request procedure, which may be the MME, sends a LocationRequest message to E-SMLC associated with the current serving cell forthe target UE, and starts the timer T3×01. The Location Request messagecontains among others an optional element UE Positioning Capability.When the UE positioning capability is unknown, the E-SMLC may request itthrough LPP.

The UE Positioning Capability provides information about the LCScapabilities of the target UE and comprises only one single informationelement, LPP Support, which is a mandatory binary indicator. If theindicator is set to TRUE, it means that the LPP is supported by the UE.

If a location estimate is requested and subsequently obtained, theE-SMLC shall return a LCS-AP Location Response to the initiator of thelocation request. If assistance data for a UE is instead requested fromthe E-SMLC, e.g. in case of UE-based positioning, and the E-SMLC is ableto successfully transfer this to the UE, the E-SMLC shall return anLCS-AP Location Response to the initiator of the location request, whichmay be the MME. This message shall not contain any parameters, as theabsence of an LCS Cause parameter in this case implies that the transferwas successful. If the MME receives the LCS-AP Location Response for thecorresponding request message, the MME shall stop the timer T3×01.

In case of unsuccessful operation, the LCS-AP Location Response messagewill contain an LCS Cause field. Upon receiving such a response message,the MME also stops the timer T3×01. In case of an expiry of the timerT3×01, the MME shall abort the procedure, release any resourcesallocated for this location request procedure and notify the node thattriggered the Location Request about the error.

LPP Positioning Procedures for Positioning Capability Exchange

Capability transfer in the LTE positioning architecture is supported inthe LPP. The signaling diagram in FIG. 4 b illustrates the LPPcapability transfer procedure involving a request(S5.RequestCapabilities) sent from the positioning server 43 to thepositioning target device 42 and a response (S6. ProvideCapabilities)sent from the target 42 to the requesting server 43.The signalingdiagram in FIG. 4 c illustrates the LPP capability indication procedureused by the target 42 to unsolicited provide capabilities to the server43. LPP procedures are not required to occur in any fixed order, e.g.,the target device may transfer capability information to the server atany time if not already performed.

In both FIGS. 4 b and 4 c, the capability is transferred from a target42 to a server 43. In the 3GPP control plane solution the wirelessdevice, e.g. a UE, is the target device and the E-SMLC is the server. Inthe user plane solution, a SUPL Enabled Terminal (SET) is the targetdevice and the SLP is the server. A UE request for capability fromE-SMLC or delivery of the E-SMLC capability to the UE is not supportedin the current standard. Furthermore, the positioning capabilitytransfer procedure described above does not currently apply to uplinkE-CID positioning.

When a target device receives a RequestCapabilities message, it shallinclude the device capabilities for each method included in the requestfor capabilities and deliver the response to the lower layers fortransmission. If the message type is an LPP RequestCapabilities and someof the requested information is not supported, the target returns anyinformation that may be provided in a normal response.

The information elements in the RequestCapabilities message are listedin FIG. 4 d. The list comprises the A-GNSS, OTDOA, and ECIDRequestCapabilities, as well as commonlEsRequestCapabilities and epduRequestCapabilities, where EPDU stands for External Protocol Data Unit.The OTDOA and ECID RequestCapabilities information elements arecurrently defined as empty sequences. The commonlEsRequestCapabilitiesinformation element is provided for future extension. Theepdu-RequestCapabilities are defined as an EPDU-Sequence containinginformation elements that are defined externally to LPP by otherorganizations.

The information elements in the ProvideCapabilities message are listedin FIG. 4 f. The message has a similar structure to that of theRequestCapabilities message. In the current standard, for OTDOA, thetarget may inform the server about the supported positioning mode. OnlyUE assisted positioning is supported so far as illustrated in FIG. 4 e,detailing the OTDOA ProvideCapabilities information element. For E-CID,the target may inform about the supported E-CID measurements, e.g.Reference Signal Received Power (RSRP), Reference Signal ReceivedQuality (RSRQ), and UE receive-transmit time difference as illustratedin FIG. 4 g, detailing the ECID ProvideCapabilities information element.

eNodeB Positioning Capabilities

The transfer of eNodeB positioning capabilities to the positioning nodeis currently not supported in the standard and there are no capabilityelements in LPPa. However, eNodeB capabilities may be transferred viaO&M.

The Multi-Carrier Concept

A multi-carrier system, also called a carrier aggregation (CA) system,allows the UE to simultaneously receive and/or transmit data over morethan one carrier frequency. The multi-carrier concept is used in bothHSPA and LTE. Each carrier frequency is often referred to as a componentcarrier (CC) or simply a serving cell in the serving sector. Morespecifically the carrier frequencies are referred to as primary andsecondary CC or serving cells.

In a multi-carrier system the primary CC carries all common andUE-specific control channels. The secondary CC may contain onlynecessary signaling information and signals. Signaling information orsignals that are UE-specific may e.g. not be present in the secondaryCC, since both primary uplink and downlink CCs are typicallyUE-specific. This means that different UEs in a cell may have differentprimary downlink CCs.

The simultaneous transmission and/or reception over the CCs enable theUE to significantly increase its data reception and transmission rates.For instance, an aggregation of two 20 MHz carriers in an LTEmulti-carrier system would theoretically lead to a doubled data ratecompared to that attained by a single 20 MHz carrier. The CCs may becontiguous or non-contiguous. Non-contiguous carriers may belong to thesame frequency band or to different frequency bands. A hybrid carrieraggregation scheme comprising both contiguous and non-contiguous CCs arealso envisaged in LTE.

An Intra-Radio Access Technology (RAT) multi-carrier system means thatall the CCs belong to the same RAT. Some examples of Intra-RATmulti-carrier systems are LTE FDD multi-carrier system, LTE TDDmulti-carrier system, UTRAN FDD multi-carrier system, UTRAN TDDmulti-carrier system. In an inter-RAT multi-carrier system, the CCs maybelong to different RATs. For example, in such systems one CC may belongto LTE FDD and another one to LTE TDD. Yet another example comprises ofCCs belonging to UTRAN FDD and E-UTRAN FDD. In inter-RAT multi-carriersystems one of the RATs may be considered as the main or primary RATwhile the remaining ones are considered as auxiliary RATs.

A multi-carrier or CA capable UE may thus in principle be able toperform measurements on a secondary CC, and equivalently on otherfrequency carriers, without gaps or compressed mode, as it comprisesmore than one transceiver. However, this measurement capability withoutgaps can either be optional or mandatory in the UE. Furthermore thiscapability may be mandatory for a certain number of secondary CC andoptional beyond that number. For example, for a multi-carrier UEsupporting up to four CCs in total, it may be mandatory for the UE tomeasure on one secondary CC (i.e. on the second carrier) withoutmeasurement gaps but optional to measure on the remaining secondary CC(i.e. on the third and fourth carriers). This means that for a UEsupporting up to two CCs in total, the measurements on the secondary CCwhich is the only secondary carrier may be mandatory.

As this measurement capability is optional, the UE has to separatelysignal the capability to the network in addition to its carrieraggregation capability signaling. Such a capability is not defined inthe current standard. If defined, it will likely be a part of the RFparameters in the UE radio access capability information describedabove.

UE Radio Access Capability and RN Node Capability Signaling toPositioning Node

The currently defined UE radio access capabilities, as well as possiblefuture UE radio access capabilities such as the measurement capabilitiesdescribed above for multi-carrier systems, may have an impact onpositioning measurement requirements and on positioning performance aswill be described hereinafter:

-   -   Inter-frequency measurements and the measurement requirements        have been standardized for LTE OTDOA. There is, however, no        standardized means to indicate to the positioning node (E-SMLC        or SLP) which frequency bands that are supported by the UE.The        positioning node does thus not know whether a cell on a        frequency other than the serving-cell frequency may be included        in the assistance data for the given UE, in order for the UE to        be able to measure that cell for positioning.    -   In multi-carrier/carrier aggregation systems, when including        cells on the secondary carrier frequency or CC in the assistance        data, the network will not know whether measurement gaps have to        be configured or not. This means that by default, the system        will always configure measurement gaps, without taking into        account the UE capability of multi-carrier measurements without        gaps or compressed mode in multi-carrier UTRA or in inter-RAT        multi-carrier with e.g. a mixture of UTRA and E-UTRA CCs. A        network node will e.g. always have to configure measurement gaps        when cells operating on different frequencies are included in        the assistance data, even if no inter-frequency measurements are        configured for the UE. This is highly inefficient since it        causes throughput loss due to unnecessary measurement gaps.        Furthermore, the system will also try to align PRS        configurations and the gaps on different frequencies        accordingly, leading to performance degradation and unnecessary        procedures.    -   When inter-frequency and/or inter-RAT positioning measurements        are requested, the system does not take into account the UE        capability of inter-frequency and/or inter-RAT measurement        without gaps. This means that the system will always try to        configure measurement gaps and/or align PRS configurations and        the gaps on different frequency accordingly, leading to        performance degradation and unnecessary procedures. The problem        of the unnecessary procedures will increase with the        introduction of multi-carrier/CA capable UEs, as there will then        be a larger number of UEs which are capable of performing        measurements without gaps.    -   The standardized RSTD measurement requirements for OTDOA        currently do not take into account the UE capability of        inter-carrier and/or inter-frequency measurement without gaps.        This means that, in case of multi-carrier and/or inter-frequency        measurements, requirements that are more relaxed will always        apply as it is assumed that measurement gaps will always have to        be used. This will have a negative impact on UE positioning        performance.    -   The maximum number of supported layers for spatial multiplexing        in downlink is currently not known to the positioning node and        thus cannot be taken into account for optimizing positioning        performance, e.g. by configuring transmit antennas accordingly.    -   Neither device type nor the UE release or the UE category is        currently known to the positioning node and thus the information        cannot be utilized for optimizing positioning performance.    -   Interference cancellation support or enhanced hierarchical        network also known as heterogenous network support are currently        not a standardized UE capability and can thus not be signaled to        any node, including the positioning node. However, this        information about the UE could be utilized by the positioning        node in the assistance data build up, as it may give an        indication which neighbor cells that may be included in the        assistance data.    -   No CSG-specific support for positioning is currently available        in the standard. The network is thus not aware of e.g. which CSG        group the UE belongs to, or whether the UE is in the coverage of        a CSG cell to which the UE may or may not belong to.

As indicated, the lack of UE radio access capability information mayresult in positioning performance degradation, even for existing andstandardized service features such as inter-frequency measurements. Ifthe positioning node is not aware of whether a certain frequency issupported by a given UE or not, the wrong cells, i.e. those which the UEwon't be able to measure, may be included in the assistance data.Therefore, according to embodiments, UE radio access capabilities aresignaled between any of the following nodes, as illustrated by S30 inthe signaling diagram in FIG. 5:

-   -   1. As described above, the MME 53 has the information related to        the UE radio access capabilities. However, this information is        not available to E-SMLC 54 in a conventional system. Therefore,        in a first embodiment, UE radio access capability information is        signaled from the MME 53 in the CN to the positioning node 54 in        S31. In one example UE radio access capability information is        signaled to the E-SMLC 54 via LCS-AP protocol over the SLs        interface. In one embodiment, the UE radio access capability        information is included in a positioning request e.g. as a part        of the “UE Positioning Capability” element. In another        embodiment, the UE radio access capability information is        included in a positioning request outside the “UE Positioning        Capability” element, e.g. as a part of another element        containing general UE capability or UE radio access capability        information. This new capability information element may be        included as an optional element. The request for the        capabilities may be transmitted from the positioning node 54 to        the MME 53, as illustrated by S25. Alternatively, no request is        transmitted at all, and the capability transfer is thus        unsolicited.    -   2. Conventionally, the UE does not report information related to        its radio access capabilities to any node related to        positioning. Therefore in a second embodiment of the invention,        the UE 51 sends its UE radio access capability information to        the positioning node 54 in S33, upon starting a session or        whenever necessary. Alternatively, the UE 51 sends this        information to the positioning node 54 upon receiving a request        from the positioning node or from any other network node. The        information can be signaled or exchanged via different protocols        and mechanisms. In one alternative embodiment, this information        is sent by the UE 51 to the positioning node 54 in S33 via the        LPP protocol. Note that since an LPP extension, e.g. LPPe, is        transmitted in an LPP message, transmitting via the LPP protocol        may also mean transmitting via an LPP extension.The UE radio        access capabilities may be included in the element(s) intended        for common capabilities, e.g. the commonlEsRequestCapabilities        and/or the commonlEsProvideCapabilities. The request for the        capabilities may be transmitted over the same protocol from the        positioning node 54 to the UE 51, as in S21. Note that no        request for UE capabilities may be transmitted at all, and the        capability transfer may thus be unsolicited. In another        alternative of this second embodiment the UE radio access        capability information is sent by the UE 51 to the positioning        node 54 in a transparent container via a radio network node 52        such as the eNodeB, which may or may not be the serving eNodeB.        The capability information may thus be encapsulated in RRC from        the UE 51 to the eNode B 52 and in LPPa from the eNodeB 52 to        the positioning node 54. The key aspect with such encapsulation        is that the eNode B 52 does not modify any information on its        way to the positioning node 54. With this alternative, the        optional request for the capabilities may be transmitted from        the positioning node 54 to the eNodeB 52 in S22 which then        triggers the capability request transmitted by eNodeB 52 to the        UE 51 in S23. The request may alternatively be transmitted from        the positioning node 54 and relayed to the UE 51 in a        transparent container in S21 e.g. encapsulated in RRC.    -   3. According to a third embodiment, the eNodeB 52 signals the UE        radio access capabilities via LPPa protocol to the positioning        node 54 in S32. It is assumed that the eNodeB is aware of these        capabilities and that there is a possibility for transmitting        such UE-associated information. For example, the eNodeB could        receive or acquire this information from either the UE or from        any other CN node, such as the MME. The signaling of this        information by MME or by the UE to eNodeB is known in prior art.        In this third embodiment, the request for the capabilities may        be received by the eNodeB 52 from the positioning node 54 in        S24, e.g. over LPPa. Alternatively, no request is transmitted at        all, and the capability transfer is thus unsolicited e.g. on        some trigger.

As already mentioned in the description of the first, second and thirdembodiments above, the UE radio access capability transfer with any ofthe above signaling solutions and between any of the described nodes maybe an unsolicited procedure, e.g. transmitted without a request for thecapability information. Alternatively, the UE radio access capabilityinformation is transmitted on request. Different options of transmittingthe request are as described above for the corresponding signalingsolutions.

At least one of the following parameters which have already beendescribed above, may be signaled as part of the UE radio accesscapabilities between the nodes according to the first, second and thirdembodiments above:

-   -   ue-Category: The parameters associated with each UE category may        be transmitted to the positioning node provided that they are        also implemented in the positioning node, i.e that the        positioning node is aware of the categories.ln one embodiment,        only a part of the ue-Category information is signalled to the        positioning node, e.g. only the maximum number of supported        layers;    -   supportedBandListEUTRA;    -   Inter-RAT parameters indicating supported bands for other RATs,        e.g. UTRA FDD, UTRA TDD, GERAN, CDMA 2000;    -   interFreqNeedForGaps;    -   interRAT-NeedForGaps;    -   accessStratumRelease, which may be useful when some features        exploited for positioning are applicable only to a certain UE        release or from a certain release;    -   device Type;    -   CSG proximity indication parameters, such as        intraFreqProximitylndication, interFreqProximitylndication and        utran-Proximitylndication;    -   Neighbor cell SI acquisition parameters, such        asintraFreqSI-AcquisitionForHO, interFreqSI-AcquisitionForHO,        utran-SI-AcquisitionForHO;    -   multi-carrier or carrier aggregation capability;    -   indication whether a multi-carrier or carrier aggregation        capable UE is also capable of performing measurements without        gaps or without compressed mode. This is valid for any UE        measurement including e.g. measurements for positioning, and        measurements for mobility;    -   indication of frequencies and/or the number of carries for which        the UE is capable of performing measurements including e.g.        measurements for positioning, and for mobility without gaps or        without compressed mode. It may e.g. be an indication that the        UE may perform measurements without gaps for carriers in        general, for contiguous carriers, and/or for non-contiguous        carriers;    -   indication whether a multi-carrier or carrier aggregation        capable UE is also capable of performing positioning        measurements in general or any specific positioning        measurements, such as RSTD measurements for OTDOA, without gaps        or without compressed mode;    -   interference cancellation capability and/or enhanced support for        operating in heterogeneous networks, e.g. UE support for        restricted measurements for heterogeneous network deployments

According to another embodiment, the radio network node 52, such as theeNodeB, may signal some of its capabilities to the positioning node 54,as illustrated with S10 in FIG. 5. The radio network node capabilitiesmay be the only capabilities signaled to the positioning node.Alternatively, the radio network capabilities are signaled in additionto the UE radio access capability information. The radio network nodecapabilities may be of assistance in the positioning to decide e.g.whether to configure the inter-frequency measurements for a particularUE or not. The signaling of the radio network node capabilities may forexample be performed using control plane protocols such as the LPPa, orusing user plane protocols.

The eNodeB may or may not support CA or may support CA for certainfrequency bands. If CA is supported by the eNodeB, the UE can measurethe inter-frequency positioning measurements according to the rulespecified for CA, e.g. without measurement gaps leading to betterperformance. The eNodeB may for example support CA only on band B1,although the UE supports CA on bands B1 and B2. Hence by using thesesets of the capability information the positioning node can configure UEto perform inter-frequency measurement on band B1.

Furthermore, a radio network node such as the eNodeB may have limitedresources such as hardware resources to process or manage a large numberof measurements performed by the UE. For example the eNodeB may be ableto configure gaps for positioning measurements for only a limited numberof UEs around the same time. As eNodeB resource information, such ashardware capability or status, number of UEs, overall load, andcomposite available capacity, is exchanged between eNodeBs over the ×2interface, the eNodeB may in embodiments signal such sets of informationor similar information to the positioning node. The positioning node maytherefore use one or more of these sets of information, to decidewhether or not a UE should be configured for inter-frequency positioningmeasurement and what type of inter-frequency positioning measurementsthat may be used, to build up the assistance data accordingly, and/or toselect a positioning method such that failures and/or delays due tooverload are minimized.

It is possible to enhance inter-frequency measurement performance andensure consistent assistance data build-up or configuration bytransmitting UE radio access capability information according to theembodiments described above. Given the information about the frequencybands supported by the UE, e.g. indicated by the UE capability parametersupportedBandListEUTRA and/or from parameters indicating supported bandsfor other RATs, the positioning node such as the E-SMLC or the SLP mayselect only the cells operating on frequencies supported by the UE forinclusion in the positioning assistance data that is transmitted to theUE.

When the UE capability information is not available, the positioningnode behavior may be pre-defined. It may e.g. assume that either allfrequencies are supported or that only the serving-cell frequency issupported. If the network transmits a cell list which includes a cell ona frequency not supported by the UE, the UE may transmit a failureindication and/or failure cause (e.g., not supported frequency) for thatcell. Currently, there is no such standardized failure cause.

The positioning node also communicates with radio network nodes, e.g.with eNodeBs over LPPa, and requests information or measurements e.g.needed for the assistance data build up. In one embodiment, thepositioning node may exploit the received UE radio access capabilityinformation on the supported bands, and may request the necessaryinformation or measurements from the cells on the frequencies that areidentified to be of interest based on the supported band information.

The network should not configure measurement gaps for positioning forUEs capable of conducting inter-frequency and/or inter-RAT measurementswithout gaps. Furthermore, the positioning requirements should also beapplied based on the UE radio access capability information related togap configuration. More stringent requirements should be applied for UEscapable of measuring without gaps and more relaxed requirements shouldbe applied for UEs requiring measurement gaps for the configuredmeasurements, such as inter-frequency or inter-RAT measurements.

The gap configuration decision may be taken in a radio network nodewhich receives the indication for a need of measurement gaps from thenetwork. The radio network node checks own information on the UE radioaccess capability, and decides accordingly. The node may e.g. decide tonot configure measurement gaps when the available UE radio accesscapability information indicates no need for gaps, or it may decide toconfigure gaps when there is no capability information available and thepositioning node indicates the need for gaps or that inter-frequencygaps are configured. Alternatively, the decision is made by the UE basedon own capability information. Still another alternative, is that thedecision is made by the positioning node based on the availableinformation about the UE radio access capability and the positioningmeasurement configuration or the assistance data for that UE.

The UE radio access capability information, based on which the need formeasurement gaps may be decided, can be acquired e.g. from the followingUE radio access capability parameters or information:

-   -   interFreqNeedForGaps;    -   interRAT-NeedForGaps;    -   accessStratumRelease, e.g. if the capability of measuring        without gaps becomes mandatory from a certain release;    -   indication whether a multi-carrier or carrier aggregation        capable UE is also capable of performing measurements without        gaps or without compressed mode;    -   multi-carrier and/or CA capability, e.g. if the multi-carrier        and/or CA capability also implies that no gaps are necessary;    -   indication whether a multi-carrier or CA capable UE is also        capable of performing positioning measurements in general or any        specific positioning measurements such as RSTD for OTDOA without        gaps or without compressed mode.

The positioning performance in heterogeneous networks may also beenhanced by utilizing the UE radio access capability information. Giventhe information on the UE radio access capability related to the abilityto effectively cancel the interference and/or related to enhancedsupport in the UE for operating in heterogeneous networks, thepositioning node may decide to include cells associated with radio basestations of different types in the assistance data. Different types ofradio base stations may e.g. be radio base stations of different powerclasses such as macro, micro, pico, home eNodeB.

Furthermore, muting of reference signals used for positioning may beavoided in the network if most of the UEs are capable of dealing withstrong interferers. To configure “no muting”, i.e. to decide that nomuting is necessary for a cell, may not require communication with othernodes when cell muting is configured by the positioning node, i.e.centrally or semi-centrally. If muting configuration is decided locallyby radio network nodes, the radio network nodes may receive anindication from another node, such as the positioning node or the MME,that most of the UEs in the area are capable of dealing with stronginterferers. Alternatively, the radio network nodes may utilize owninformation or statistics about this type of UE capability in the area.

The UE radio access capability information and the eNodeB capabilityinformation may also be used for configuring antennas transmittingreference signals used for positioning. The beam-forming capability orthe number of receive antennas at the UE and/or eNodeB side which may besignaled to the positioning node similarly to other capabilitiespreviously described, may be utilized in the positioning node whenbuilding up the assistance data, when calculating the UE position, andwhen utilizing measurements for AECID and fingerprinting. Differentdatabases, such as Radio Frequency fingerprinting databases and AECIDdatabases may e.g. be supported for measurements with and withoutbeam-forming. The ability to use a dedicated antenna for positioning mayalso be considered as an eNodeB capability, which may be signaled to andutilized by the positioning node.

UE radio access capability information and eNodeB capability informationmay be used in deployment scenarios with so called femto cells for ahome eNodeB. A home eNodeB or any home base station may belong to anopen access or a CSG class. The CSG is owned and at least partly managedby the subscriber, and the operator thus has less control over the CSGoperation. Hence in the CSG case it may not be feasible or notsufficiently reliable that the UE performs the positioning measurements,as a CSG cell may be turned off anytime or its location may be changedby the subscriber anytime. If the home base station sends its capabilityinformation related to CSG to the positioning node, the positioning nodemay decide whether to include certain cells in the assistance data ornot.

The UE capability of dealing with femto cells may also be accounted forin the positioning when building up the assistance data, e.g. whendeciding whether to include femto cells in the neighbor cell list ornot. Such a radio access capability may e.g. be the CSG proximityindication, or an advanced cell selection technique indicating that theUE does not switch to a femto cell in case a strong interference from ahigher power node may be expected or the other way around, or that theUE is allowed to join a hybrid femto cell, i.e. a combined CSG/non-CSGfemto cell.

The positioning node may also utilize energy-saving and/or power-savingrelated capability information of UEs and eNodeBs. The eNodeB may e.g.operate in a power saving mode transmiting signals relativelyinfrequently or turning off transmission over a period of time, and theeNodeB may send such capability information to the positioning node as apart of the radio network node capability. Furthermore, when the eNodeBchanges to the power saving mode it may indicate this to the positioningnode. The eNodeB may also provide detailed information about the powersaving period such as the time duration of power saving, and thediscontinuous transmission cycle length including on and off periods.The positioning node may thus take into account this power savingcapability of the eNodeB when deciding to configure the UE for doingpositioning measurements, in order to optimize positioning performance.

Furthermore, the parameter deviceType which defines whether the devicedoes not benefit from NW-based battery consumption optimisation, may beused by the positioning node to decide the positioning method orpositioning configuration for the given UE. The positioning methods orpositioning configurations have different characteristics from theenergy-saving and/or power-saving point of view and thus may bediscriminated based on the related UE radio access capabilityinformation.

Consequently, advantages provided by the above described methods are oneor more of the following:

-   -   The positioning node is aware of UE radio access capabilities        and thus has more flexibility and more information when        configuring for positioning.    -   The positioning node is aware of eNodeB capabilities and thus        has more flexibility and more information available that may be        used to enhance positioning or optimize positioning        configuration in the network.    -   True multi-carrier operation for positioning is enabled.    -   Positioning performance is enhanced also for coming LTE releases        accounting for advanced UE capabilities.

FIG. 6 is a flowchart of the method in the positioning node of awireless communication system, according to embodiments of theinvention. The method supports wireless device positioning. The wirelessdevice may be a UE. The method comprises:

-   -   610: Receiving at least one of the following: radio access        capability information associated with a wireless device; and        capability information associated with a radio network node from        the radio network node. The radio access capability information        is in the first embodiment received from a core network node,        and may be received in a positioning request. The radio access        capability information is in the second embodiment received from        the radio network node, and in the third embodiment from the        wireless device. The first, second and third embodiments are        described in more details above. The received radio access        capability information may in embodiments comprise a list of        frequency bands supported by the wireless device, and the list        may correspond to a supportedBandListEUTRA parameter in LTE. The        received radio access capability information may additionally or        alternatively comprise information related to at least one of        the following: a carrier aggregation capability; a capability of        performing measurements without measurement gaps on at least one        of a secondary carrier in carrier aggregation, an        inter-frequency carrier and an inter-RAT carrier; an        interference cancellation capability; and a capability of        operation in heterogeneous networks. However, any of the        parameters described previously as being part of the UE radio        access capability information may be received by the positioning        node comprised in the radio access capability information. The        received capability information associated with the radio        network node may comprise information related to at least one of        the following: a carrier aggregation capability; a resource        capability; and a power saving capability.    -   620: Supporting positioning of the wireless device based on the        received radio access capability information associated with the        wireless device and/or the capability information associated        with the radio network node. The supporting of positioning of        the wireless device may in embodiments comprise supporting at        least one of: assistance data build up; requests for information        necessary for positioning; positioning measurements;        configuration of measurement gaps for positioning measurements;        a definition of positioning requirements; enhanced positioning        performance in a heterogeneous network; configuration of        antennas transmitting reference signals for positioning, and        configuration of reference signal muting.

In one embodiment, the method further comprises transmitting, in 605, arequest for the radio access capability information before receiving theradio access capability information in 610.

FIG. 7 is a flowchart of the method in a wireless device of a wirelesscommunication system, of supporting positioning of the wireless device,the positioning being managed by a positioning node. The wireless devicemay be a UE. The method comprises:

-   -   710: Transmitting radio access capability information associated        with the wireless device to the positioning node. The        transmitted radio access capability information may in        embodiments comprise a list of frequency bands supported by the        wireless device, and the list may correspond to a        supportedBandListEUTRA parameter in LTE. However, any of the        parameters described previously as being part of the UE radio        access capability information may be transmitted to the        positioning node comprised in the radio access capability        information.

In one embodiment, the method further comprises receiving a request forthe radio access capability information, in 705, before transmitting theradio access capability information. The request for the radio accesscapability information may be received from the positioning node or froma radio network node controlling the wireless device.

FIG. 8 is a flowchart of the method in the radio network node of awireless communication system, of supporting positioning of a wirelessdevice controlled by the radio network node. The positioning is beingmanaged by a positioning node connected to the radio network node. Thewireless device may be a UE. The method comprises:

-   -   810: Transmitting at least one of the following to the        positioning node: radio access capability information associated        with the wireless device, and capability information associated        with the radio network node. The transmitted radio access        capability information may in embodiments comprise a list of        frequency bands supported by the wireless device, and the list        may correspond to a supportedBandListEUTRA parameter in LTE.        However, any of the parameters described previously as being        part of the UE radio access capability information may be        transmitted to the positioning node comprised in the radio        access capability information.

In one embodiment, the method further comprises receiving a request forthe radio access capability information, in 805, from the positioningnode, before transmitting the radio access capability information.

FIG. 9 is a flowchart of the method in the core network node of awireless communication system, of supporting positioning of a wirelessdevice associated with the core network node. The positioning is managedby a positioning node connected to the core network node. The wirelessdevice may be a UE. The method comprises:

-   -   910: Transmitting radio access capability information associated        with the wireless device to the positioning node. The radio        access capability information may be transmitted in a        positioning request. The transmitted radio access capability        information may in embodiments comprise a list of frequency        bands supported by the wireless device, and the list may        correspond to a supportedBandListEUTRA parameter in LTE.        However, any of the parameters described previously as being        part of the UE radio access capability information may be        transmitted to the positioning node comprised in the radio        access capability information.

In one embodiment, the method further comprises receiving a request forthe radio access capability information, in 905, from the positioningnode, before transmitting the radio access capability information.

The positioning node 1000 for a wireless communication system isschematically illustrated in FIGS. 10 a-10 c, according to embodiments.The positioning node 1000 comprises a receiving unit 1010 adapted toreceive at least one of the following: radio access capabilityinformation associated with a wireless device; and capabilityinformation associated with a radio network node from said radio networknode. The wireless device may be a UE. The receiving unit 1010 may inone embodiment, corresponding to the first embodiment described above,be adapted to receive the radio access capability information from theCN node 1300, as illustrated in FIG. 10 c, e.g. in a positioningrequest. In another embodiment corresponding to the second embodimentdescribed above, the receiving unit 1010 is adapted to receive the radioaccess capability information from the radio network node 1200, asillustrated in FIG. 10 b, and in an alternative embodiment correspondingto the third embodiment described above, it is adapted to receive theradio access capability information from the wireless device 1100, asillustrated in FIG. 10 a. The received radio access capabilityinformation may in embodiments comprise a list of frequency bandssupported by the wireless device, and the list may correspond to asupportedBandListEUTRA parameter in LTE. The received radio accesscapability information may additionally or alternatively compriseinformation related to at least one of the following: a carrieraggregation capability; a capability of performing measurements withoutmeasurement gaps on at least one of a secondary carrier in carrieraggregation, an inter-frequency carrier and an inter-RAT carrier; aninterference cancellation capability; and a capability of operation inheterogeneous networks. However, any of the parameters describedpreviously as being part of the UE radio access capability informationmay be received by the positioning node comprised in the radio accesscapability information. The received capability information associatedwith the radio network node may comprise information related to at leastone of the following: a carrier aggregation capability; a resourcecapability; and a power saving capability.

The positioning node also comprises a positioning support unit 1020adapted to support positioning of the wireless device based on thereceived radio access capability information associated with thewireless device and/or the capability information associated with theradio network node. The positioning support unit 1020 is in embodimentsadapted to support at least one of: assistance data build up; requestsfor information necessary for positioning; positioning measurements;configuration of measurement gaps for positioning measurements; adefinition of positioning requirements; enhanced positioning performancein a heterogeneous network; configuration of antennas transmittingreference signals for positioning, and configuration of reference signalmuting.

In other embodiments, the positioning node also comprises a transmittingunit 1005 adapted to transmit a request for the radio access capabilityinformation, either to the CN node, the radio network node, or thewireless device.

The wireless device 1100 for a wireless communication system isschematically illustrated in FIG. 10 a, according to embodiments. Thewireless device may be a UE, and is configured to support positioningmanaged by a positioning node. The wireless device comprises atransmitting unit 1110 adapted to transmit radio access capabilityinformation associated with the wireless device to the positioning node.In embodiments, the wireless device further comprises a receiving unit1105 adapted to receive a request for the radio access capabilityinformation. The receiving unit 1105 may be adapted to receive therequest for the radio access capability information from the positioningnode or from a radio network node controlling the wireless device.

The radio network node 1200 for a wireless communication system isschematically illustrated in FIG. 10 b, according to embodiments. Theradio network node may for example be an eNodeB. The radio network node1200 is configured to support positioning of a wireless device, whichmay be a UE, controlled by the radio network node, the positioning beingmanaged by a positioning node connectable to the radio network node. Theradio network node comprises a transmitting unit 1210 adapted totransmit at least one of the following to the positioning node: radioaccess capability information associated with the wireless device, andcapability information associated with the radio network node. Inembodiments, the radio network node further comprises a receiving unit1205 adapted to receive a request for the radio access capabilityinformation from the positioning node.

The CN node 1300 for a wireless communication system is schematicallyillustrated in FIG. 10 c, according to embodiments. The CN node isconfigured to support positioning of a wireless device associated withthe CN node, the positioning being managed by a positioning nodeconnectable to the CN node. The wireless device may be a UE. The CN node1300 comprises a transmitting unit 1310 adapted to transmit radio accesscapability information associated with the wireless device to thepositioning node, in one embodiment in a positioning request. Inembodiments, the wireless device further comprises a receiving unit 1305adapted to receive a request for the radio access capability informationfrom the positioning node.

The units described above with reference to FIGS. 10 a-c are logicalcircuits and do not necessarily correspond to separate physicalcircuits.

FIG. 10 d schematically illustrates an embodiment of the positioningnode 1000, which is an alternative way of disclosing the embodimentsillustrated in FIGS. 10 a-c. The positioning node 1000 comprises areceiving unit 1010 as already described with reference to FIGS. 10 a-c.The receiving unit 1010 may be integrated in hardware of the positioningnode 1000. In other embodiments, the positioning node also comprises atransmitting unit 1005 as described above with reference to FIGS. 10a-c. The positioning node 1000 also comprises a processing unit 1054which may be a single unit or a plurality of units. Furthermore, thepositioning node 1000 comprises at least one computer program product1055 with a computer readable medium in the form of a non-volatilememory, e.g. an EEPROM (Electrically Erasable Programmable Read-OnlyMemory), a flash memory or a disk drive. The computer program product1055 also comprises a computer program 1056 stored on the computerreadable medium, which comprises code means which when run on thepositioning node 1000 causes the processing unit 1054 on the positioningnode 1000 to perform the steps of the procedures described earlier inconjunction with FIG. 6.

Hence in the embodiments described, the code means in the computerprogram 1056 of the positioning node 1000 comprises a positioningsupport module 1056 a for supporting positioning of the wireless devicebased on the received radio access capability information associatedwith the wireless device and/or the capability information associatedwith the radio network node. The code means may thus be implemented ascomputer program code structured in computer program modules. The module1056 a essentially performs the step 610 of the flow in FIG. 6 toemulate the positioning node described in FIGS. 10 a-c. In other words,when the modules 1056 a is run on the processing unit 1054, itcorresponds to the unit 1020 in FIGS. 10 a-c.

Although the code means in the embodiment disclosed above in conjunctionwith FIG. 10 d are implemented as a computer program module which whenrun on the positioning node 1000 causes the node to perform the stepdescribed above in conjunction with FIG. 6, the code means may inalternative embodiments be implemented completely or partly in firmware,hardware or combinations thereof.

It will be appreciated that the methods and devices described above canbe combined and re-arranged in a variety of equivalent ways, and thatthe methods can be performed by one or more suitably programmed orconfigured digital signal processors and other known electronic circuits(e.g., discrete logic gates interconnected to perform a specializedfunction, or application-specific integrated circuits). Many aspects ofthis invention are described in terms of sequences of actions that canbe performed by, for example, elements of a programmable computersystem.

It will be appreciated that procedures described above are carried outrepetitively as necessary, for example, to respond to the time-varyingnature of communication channels between transmitters and receivers.

Moreover, this invention can additionally be considered to be embodiedentirely within any form of computer-readable storage medium havingstored therein an appropriate set of instructions for use by or inconnection with an instruction-execution system, apparatus, or device,such as a computer-based system, processor-containing system, or othersystem that can fetch instructions from a storage medium and execute theinstructions. As used here, a “computer-readable medium” can be anymeans that can contain, store, or transport the program for use by or inconnection with the instruction-execution system, apparatus, or device.The computer-readable medium can be, for example but not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, or device. More specific examples (anon-exhaustive list) of the computer-readable medium include anelectrical connection having one or more wires, a portable computerdiskette, a random-access memory (RAM), a read-only memory (ROM), anerasable programmable read-only memory (EPROM or Flash memory), and anoptical fiber.

Thus, the invention may be embodied in many different forms, not all ofwhich are described above, and all such forms are contemplated to bewithin the scope of the invention. For each of the various aspects ofthe invention, any such form may be referred to as “logic configured to”perform a described action, or alternatively as “logic that” performs adescribed action.

As described above, methods and apparatus in accordance with thisinvention include, but are not limited to, one or more of the followingaspects:

-   -   On signaling, the involved interfaces and the nodes    -   On methods and procedures in different nodes

In addition, when relevant, the embodiments apply both for the userplane and control plane positioning solutions, as well as between theuser-plane positioning node (SLP) and the control-plane positioning node(E-SMLC). Also, the invention is not limited to a specific positioningmethod and applies, for example, for OTDOA, E-CID or any other externalpositioning method, or even UTDOA where UE and/or eNodeB capabilitiescan be communicated to the positioning node.

ABBREVIATIONS

-   3GPP Third Generation Partnership Project-   A-GNSS Assisted-Global Navigation Satellite System-   A-GPS Assisted GPS-   AoA Angle of Arrival-   CA Carrier Aggregation-   CC Component Carrier-   CN Core Network-   CPICH Common Pilot Channel-   CRS Cell-specific Reference Signal-   CSG Closed Subscriber Group-   E-CID Enhanced Cell Identity-   eNodeB evolved Node B-   E-SMLC Evolved SMLC-   E-UTRAN Evolved Universal Terrestrial Radio Access Network-   FDD Frequency Division Duplex-   GPS Global Positioning System-   LCS-AP Location Service Application Protocol-   LPP LTE Positioning Protocol-   LPPa LPP Annex-   LTE Long-Term Evolution-   MME Mobility Management Entity-   OFDM Orthogonal Frequency Division Multiplex-   OTDOA Observed Time Difference Of Arrival-   PCI Physical Cell Identity-   PDCCH Physical Downlink Control Channel-   PLMN Public Land Mobile Network-   PRS Positioning Reference Signal-   RAT Radio Access Technology-   RB Resource Block-   RBS Radio Base Station-   RE Resource Element-   RRC Radio Resource Control-   RS Reference Signal-   RSTD Reference Signal Time Difference-   SFN System Frame Number-   SI System Information-   SINR Signal-to-Interference Ratio-   SLP SUPL Location Platform-   SMLC Serving Mobile Location Center-   SUPL Secure User Plane Location-   TA Timing Advance-   TAU Tracking Area Update-   TDD Time Division Duplex-   UE User Equipment-   UMTS Universal Mobile Telecommunications System-   UTDOA Uplink Time Difference Of Arrival

The invention claimed is:
 1. A method, in a positioning node of awireless communication system, of supporting wireless devicepositioning, the method comprising: receiving radio access capabilityinformation associated with a wireless device, wherein the radio accesscapability information comprises a list of frequency bands supported bythe wireless device; and supporting positioning of the wireless devicebased on the received radio access capability information associatedwith the wireless device, wherein supporting the positioning comprisesselecting only cells operating on frequencies from the list of frequencybands for inclusion in positioning assistance data transmitted to thewireless device.
 2. The method according to claim 1, wherein the radioaccess capability information is received from a core network node. 3.The method according to claim 1, wherein the radio access capabilityinformation is received from the radio network node.
 4. The methodaccording to claim 1, wherein the radio access capability information isreceived from the wireless device.
 5. The method according to claim 2,wherein the radio access capability information is received in apositioning request.
 6. The method according to claim 1, furthercomprising transmitting a request for the radio access capabilityinformation before receiving the radio access capability information. 7.The method according to claim 1, wherein the list of frequency bandssupported by the wireless device corresponds to a supportedBandListEUTRAparameter.
 8. The method according to claim 1, further comprisingreceiving network-side capability information associated with a radionetwork node, wherein the received network-side capability informationassociated with the radio network node comprises information related toat least one of the following: a carrier aggregation capability; aresource capability; and a power saving capability.
 9. The methodaccording to claim 1, wherein supporting positioning of the wirelessdevice comprises supporting at least one of: assistance data build up;requests for information necessary for positioning; positioningmeasurements; configuration of measurement gaps for positioningmeasurements; a definition of positioning requirements; enhancedpositioning performance in a heterogeneous network; configuration ofantennas transmitting reference signals for positioning; andconfiguration of reference signal muting.
 10. A method in a wirelessdevice of a wireless communication system, of supporting positioning ofthe wireless device, the positioning being managed by a positioningnode, the method comprising: transmitting radio access capabilityinformation associated with the wireless device to the positioning node,wherein the transmitted radio access capability information comprises alist of frequency bands supported by the wireless device; and receivingpositioning assistance data from the positioning node, the positioningassistance data being based on the radio access capability information,wherein all cells included in the positioning assistance data operate onfrequencies from the list of frequency bands.
 11. The method accordingto claim 10, further comprising receiving a request for the radio accesscapability information before transmitting the radio access capabilityinformation.
 12. The method according to claim 11, wherein the requestfor the radio access capability information is received from thepositioning node or from a radio network node controlling the wirelessdevice.
 13. A positioning node for a wireless communication system, thepositioning node comprising one or more processing circuits configuredas: a receiving unit adapted to receive radio access capabilityinformation associated with a wireless device, wherein the radio accesscapability information comprises a list of frequency bands supported bythe wireless device; and a positioning support unit adapted to supportpositioning of the wireless device based on the received radio accesscapability information associated with the wireless device, by selectingonly cells operating on frequencies from the list of frequency bands forinclusion in positioning assistance data transmitted to the wirelessdevice.
 14. A wireless device for a wireless communication system, thewireless device being configured to support positioning managed by apositioning node, and comprising one or more processing circuitsconfigured to: transmit radio access capability information associatedwith the wireless device to the positioning node, wherein the radioaccess capability information comprises a list of frequency bandssupported by the wireless device; and receive positioning assistancedata from the positioning node, the positioning assistance data beingbased on the radio access capability information, wherein all cellsincluded in the positioning assistance data operate on frequencies fromthe list of frequency bands.
 15. The wireless device according to claim14, wherein the wireless device is a user equipment.